Floating dry dock



May 24,1949. FR, HARRIS 2,471,065

FLOATING DRY DOCK l`. MMM

May 24, 1949. F. R. HARRIS FLOATING DRY DOCK Filed Feb. l, 1946 2 Sheets-Sheet 2 INVENTR.

RJR

Patented May 24, 1949 UNITED STATES PATENT OFFICE FLOATING DRY DOCK Frederic R. Harris, New York, N. Y.

Application February 1, 1946, Serial No. 644,703

7 Claims. (Cl. 114-46) My invention relates to oating dry docks, and particularly to a fioating dry dock of such construction as to permit inspection, cleaning and repairs of the underwater parts thereof in a safe and expeditious manner.

The invention set forth herein is an improvement upon the floating dry dock of my Patent No. 2,325,607, granted August 3, 1943, which covers a design comprising a center section and two end sections, without enlarged side Walls.

An important object of this invention to simplify the construction of the end parts or sections and to produce a center section with strong projecting or overhanging extensions of the side walls at their extremities. An advantage of this design is that the end sections, when lifting the center section for self-docking, are closer together than in the dock of my aforesaid patent, thus reducing to some extent the bending moment imposed upon the center section.

In its preferred form, the side Walls of the center section are carried out, with no reduction in width, to the full 1ength of the assembled dock. The end sections can be lowered, moved under the center section and then unwatered, thus lifting the center section by an upthrust directly upon the side walls under the overhanging extensions thereof. The side walls of the end sections are of a height only a few feet high above the pontoon deck. The side walls for the remainder of their height at the ends are integral with the center section and form the overhanging extensions aforesaid, to which the end sections are normally made fast in the regular operation of the dock for lifting and floating ships.

When it is desired to raise the center section, guide arms are attached to the end sections. Rollers on the ends of the arms engage vertical guide channels on the center section and permit the end sections to move vertically downward, while being restrained from any sidewise movement that might be induced by tidal currents, waves, etc. The end sections will be flooded to obtain a slight negative buoyancy and their descent will be restrained and controlled by cables. When the end sections have been submerged to the desired depth, the rollers at the extremities of the arms reach the bottom of vertical guide channels and in this position will be opposite the ends of horizontal guide channels on the center section connected to the vertical channels.

The end sections, with slight negative buoyancy, are then impelled under the center section. In this position, with the necessary blocking in place, the end sections are unwatered by compressed air or by pumps. During the sinking of the end sections, they would have positive stability at all times. After the water plane is eliminated by submersion, the center of gravity of the end sections is below the center of buoyancy, thus ensuring the positive stability required.

During the lifting of the center section, the stability is first assured by the water plane of this section. Before this water plane is extinguished, the low side walls of the end section emerge thus forming water planes which provide the necessary stability to complete the operation.

A dock of this type `can be constructed at one place and delivered overseas, with fully erected side Walls on the end sections. The latter can be berthed on the center section. At destination, the end sections can be floated into place and the side Walls thereon welded or otherwise affixed to the side walls of the center section. The presence of overhanging side Walls on the lcenter section at sea can :be avoided by constructing the overhanging parts separately and stowing them between the side walls of the center section along with the end sections in the same place while enroute, and Welding them in place when the voyage is ended.

In the drawings:

Figure 1 shows in plan a preferred form of my improved floating dry dock made of a center section and two end sections.

Figure 2 is a side elevation thereof with one end in lowered or submerged position.

Figure 3 is a side elevation and shows the cen ter section docked on the end sections.

Figure 4 is an end elevation of what appears in Figure 3.

Figure 5 is an end elevation of my improved dry dock with the three main parts or sections as they appear in Figure 1.

In the drawing the same reference characters identify the same parts.

The structure disclosed herein is the preferred form of my invention but in practice changes consistent with the nature of the invention may be made without deviating from the principle underlying same.

The drydock of this invention comprises a relatively long center section I and two end sections 2.

The center section comprises a pontoon hull 3 and two side walls 4 which give the section a trough-like shape. All the sections are preferably provided with rounded bottoms and a central buoyancy chamber C, which divides the sections laterally into two pumping compartments. This chamber will be of proper size. length or width.

Each of the side walls 4 has a projecting or overhanging portion 5 at each end; these portions extending beyond the extremities of the hull 3. These extensions 5 are of the same transverse thickness as the walls II, and have their lower faces a little above the level of the deck 6 of the hull 3. They can be built separately and welded or otherwise aixe'dltof-the sideezwalls 4I. Theside walls 'I of"th'e`en"d sections are relatively low in height; the end sections 2 are about as long as the extensions 5; and when the walls l are under and in contact with the extensions 5 thecenter.

and end sections float on the water at substantially the same level. A hinged outrigger 'on world platform 8 is preferably attached to each. end section.

On the outboard faces of the main side walls` 4 are guide channels 9.', just above the chines II..- These.channelsfhave'portions thatfare horizontal-ando-un fromitheends ofthe hullfhalong thewa-lls 4+-towardsftheeiniddle=oii the dook. and these," horizontal. portions connect` with vertical portions atthe. ends--of thehull. that run up; to-. werdet-the topsnotthe wallsdi Atttheadjacent ends the sections 2 are equipped with armsA II carryingrollers4 I 2.' that engage: the channels .9:

Qn-i the. inboard-r faces `of.y the overhanging: projectionss of. the side walls livare similar. guide channels.V I3 having horizontal portions running along-:the'flower` edgesfof the. projections 5.,.,with verticalconnecting.portionsatnthe extremities .of the overhangs; 5.=running, upto-theA topsof the latten.. Gn.v thev adjacentvv corners-of; the ends. 2., adjacentith'e. inboard. faces` of the, walls 'I are posts-14.011 Whicharelnounted rollers I2.which enter.L theguide channels- I 3.1

Gini the tops of.. the overhanging, extensions- 5 at.thefends-,- andat. the vends of the ypontoon..\:eck 6.. ini the middle. are bearings, for gnidepulleys over. which lines. are passedto each. endsection todae,.-secured;y thereto at. three.. points.. Thelines over these pulleys are kepti taut. byr a suitable meanstovmaintain the. controlV ofVV theends. 2 as they are rsunk or. raised.

For the usual operation o raising shipsthe ends 2 are attached to the center. I inthe, positions shownfinFignres l. and.5 andlattthele-Et of lligune.-r 2.. The sectionsare. secureditogether in any suitable way and thewalls limay be.. affixed to.the.foverhangs 5.,. 'llhefdocnis then sunk-and pumped out as :one lpiece... Therollers. I2.'Lare;tlien all., at,y the. topsv of the. verticali portions., of'` the channels il and.y I3, -Or the members Il. and.. I4 with. the. rollers |.2=.l may. at. this time` be4 dismounted.

'llodoclLthecenter I,. the ends are floodedsand sunkto thepositiorrshown. at .the right ,oIFigure 2". The members IIandlMlare rstmountedin their. respective positions. The. rollers on. the members I I' and'Hi'now drop to the level.' of 'the horizontal parts of theguide channels 9fandll3. Theends'Z-are now impelled under theexti'emities oftliecenter llas shown on Figure 3'. When pumped'outLthe. ends. 2"'li1t.` the, center I` tillits bottom is out of'water. At thistimethe. tops ofithe walls] on the ends 2` carry, sloping .blocks L11 to. engage theround.' bottom. of). the. center I along the sides thereof, and the middle .Yoftlie pontoon hull.3 restsvr on keel blocks I8.

vliien movingL under't'he center I' the ends 2 musizioficourse bez-sunk Vfar. enoughl. in. the'water foritl'ieblocks I I"to. clear the .bott'om,1oflthe"'cen ters, "Tlerefree the. liorizontal portions: .off 'the channels 9 and I3 are low enough on the center I and the arms II and posts I4 are of suicent length. But when the ends are under the center as far as the horizontal portions of the channels 9 and I3 permit, the ends must be allowed to rise a little till the blocks I'I make contact with the center part I. For this purpose the adjacent or the inner ends of the horizontal portions of the channels 9 and i3 have upward extending recessesshown at'v S and' I3f'respe'ctively'to allow upwardmovement of th'c'armsI Iiandip'osts I4 till the blocks I'I engage the round bottom of the center I.

Gf course the guide channels can be disposed elsewhere than as shown in any suitable relation andthe-.samemode of operation and results obtained..

To dock the ends 2, they are freed from the center. Ii and the latter is sunk. The ends are shorter than the distance between the walls Il of the center i; Withtne centery Ivsubmergedethe ends are. turned :and -iioated ,sidevvisel into ythe'wcenten Ivbetween the Wallsgasin the-dock of my prior patentl aforesaid.- vThen the? center is pumped out and raised andthe-ends=-arerraised with,it.l They `come to restzonsimil'arblocks-and they-canine inspected', cleaned and repairedat any. point,4 including their bottoms.

Infy this: position; too, the rdock: can make a.l voyage, the center/I: carrying-e. the.: ends. 2iand'rbeing theV only partailoat `onV thefwater.. Theoverhanging?v projections: 5: mightr be detachedat this ztime and: stowed oni-the. pontoon 3 adongzwitl'rzthe ends 2; being: boltedI or otherwise"securedfinzplaceliand lief affixedy imposition to-thewallsz drgwhenithe voyageis completed.

Having. described.y my invention, .'wliatz- If claim as-new is:

l: A. floating dry" do'clc. having-sections;` com'T prising a center andends; andfmeanszcomprising channelsofipredet'erminedflength-@oni'one.'section, and! parts on thel remaining; sections engaging said" channels. for permitting. limitedv'lrelative movementcf said: center and'.endsvin'vbothfa"A horie zontal rand lvertcaldirection.

2.... 'lhesdryfe dock oficlaimsl, wherein saidclian.- nelshave .f b'oth ,f horizontal; and." verticali portions.

3. The fdry"doclr accordinggto clairnl,A wherein theacenter carries, therhanrrelsfandssa'id parts ari-r` on.4 the.l ends, and yhfitve rollerssto tengagex' said channels..

ai. oating dry` dooie. a. center.' section withiaideck and: mami side awalls'itliereonhaving 'overhanging extensions projecting: beyond" the extremities'rosaid.center! section;A .said extensions bein-g: above-1 said;l deck; andi endf sections` having loxvfside: walls thereon, .tozunderlie'end engagey the lower: faces oil said' extensionsone offsaidf sec'- tions: having." channels: of predetermined length, andixthefotherzsections havingparts-engaging said channels; to. permit limitedf.- relative motionsof saidfcenteri'an'd end; sectionsein \b`oth 'an horizontal -anda/ertica'l direction.x

5.: The iioa'ting.` dryfdockaccording 'tof-claim'-4, wh'ereinsaid'-center section-'Hals said channels and theJlatter-have verticalr and "horizontal" portions landthe'endisections` bear' the'parts which en'- gage` said' channels.

6." Thedry dockaccordingto'claim; wherein the' center section has saidclraznneis,y and". the latter are' disposedon the'inboardfaces'ofsaid extensions and the outboard' faces of' the remainder'of;saidwalls, and"`said"parts are onthe endtsections andfengaefe allsaidchannel's;

L The floating dry dock according to claim 4, wherein said center section has said channels, which are horizontal, with Vertical portions at one extremity and upward extending recesses at their opposite extremities, said channels being on the inboard faces of the extensions and the outboard faces of the remainder of said Walls, and said parts are on the end sections and engage said channels.

FREDERIC R. HARRIS.

REFERENCES CITED The following references are of record in the le of this patent:

Number Number UNITED STATES PATENTS Name Date Donnelly Mar. 5, 1912 Harris Aug. 3, 1943 FOREIGN PATENTS Country Date Greait Britain Aug. 7, 1913 

